Holocene Key-Marker Tephra Layers in Kamchatka, Russia

Abstract

correlation of certain stratigraphic levels in various deposiDetailed tephrochronological studies in Kamchatka Peninsula, tional successions. Their ages being determined, they beRussia, permitted documentation of 24 Holocene key-marker come excellent time markers and can be used in geochronotephra layers related to the largest explosive eruptions from 11 logical investigations. Tephra (volcanic ash) horizons are volcanic centers. Each layer was traced for tens to hundreds of among the best marker beds of this kind. C yr B.P.) SH 2 (É1000 yr B.P.) and SH 3 (É1400 yr B.P.) from is a few tens of centimeters thick in areas distant from the Shiveluch volcano; KZ (É7500 yr B.P.) from Kizimen volcano; active volcanoes and increases up to several meters at their KRM (É7900 yr B.P.) from Karymsky caldera; KHG (É7000 yr foot. This cover provides a continuous record of the explo-B.P.) from Khangar volcano; AV 1 (É3500 yr B.P.), AV 2 (É4000 sive eruptions during the Holocene, while earlier ash layers yr B.P.), AV 4 (É5500 yr B.P.), and AV 5 (É5600 yr B.P.) from in Kamchatka were almost everywhere destroyed during Avachinsky volcano; OP (É1500 yr B.P.) from the Baraniy Amfi-Late Pleistocene glaciation and occur as isolated beds. stratigraphic value and 9 important local marker ash layers.from Shtyubel cone in Ksudach volcanic massif; and KO (É7700 yr B.P.) from the Kuril Lake-Iliinsky caldera. Tephra layers SH 5 Identification of tephra sources was possible due to prelimi-(É2600 yr B.P.) from Shiveluch volcano, AV 3 (É4500 yr B.P.) nary studies that included detailed mapping of the Holocene from Avachinsky volcano, OP tr (É4600 yr B.P.) from Opala vol-eruptive centers (Melekestsev et al., 1974) and investigations cano, KS 3 (É6100 yr B.P.) and KS 4 (É8800 yr B.P.) from Ksudach of geochemical types and petrology of Late Cenozoic volcacalderas, KSht 1 (É1100 yr B.P.) from Shtyubel cone, and ZLT nic rocks (Volynets, 1994). These data allowed us to identify

Sediment provenance variations in the southern Okhotsk Sea over the last 180 ka: Evidence from light and heavy minerals

“…Mineral assemblage comprises by volcanic glass, plagioclase, pyroxene and magnetite. Volcanic glass dominates in tephra (Braitseva et al, 1997). In the lower part of core OS03-1 (MIS 6), the contents of brown volcanic glass and cinder are high, whereas in the upper section (MIS 5 and 3), the content of transparent volcanic glass exhibited a similar trend with high values.…”

Sector collapses and large landslides on Late Pleistocene–Holocene volcanoes in Kamchatka, Russia

“…Avachinsky volcano (Braitseva et al, 1997b). The basaltic andesitic cone formed in several spurts of activity between 3600 and 3000 14 C years BP.…”

Morphometric and morphological development of Holocene cinder cones: A field and remote sensing study in the Tolbachik volcanic field, Kamchatka

“…rate of pyroclasts and lava volume) and chemical composition to those of the Northern Fissure eruption. We can reasonably assume that the above peculiarities of magnesia basalt cinder cone formation and the dynamic parameters of their eruption had been characteristic for the older cinder cones which started forming at the Tolbachik field ca 2000 BP (Braitseva et al, 1997).…”

“…The lavas and pyroclastic rocks of the Northern Fissure had similar chemical composition and are mostly magnesia medium alkaline basalts (49.54-49.75% of SiO 2 , 9.84-10.21% MgO, 2.38-2.44% Na 2 O, 0.97-1.02% K 2 O) according to 35 samples analyzed (Braitseva et al, 1997).…”